System for estimating the remaining life of a print cartridge

ABSTRACT

A printing system is described. The printing system includes a printer capable of utilizing print material contained by a cartridge. The printer is capable of detecting when the level of the print material is at a different one of a plurality of pre-determined levels. The printer is also capable of counting pixels. The printer can periodically estimate the remaining life of the cartridge using a reference print material level and the change in pixel count since the print material was at the reference material level.

BACKGROUND

Many printing devices make use of a replaceable print cartridge. Thecartridge typically contains a print material (e.g., toner or ink) thatis consumed during a printing operation.

There have been efforts in the past to develop systems that monitor theremaining life of a print cartridge in a printing device. Ways areneeded, however, to improve these systems.

It is noted for the later discussion that the “remaining life” of aprint cartridge refers to the present capacity of the cartridge to printadditional pages. One way, for example, the remaining life of acartridge may be expressed is as a percentage of the original capacity.

For example, if none of the original amount of print material in acartridge has been consumed, the remaining life of the cartridge may besaid to be at “100%”. If 50% of the original print material is consumed,the remaining life of the cartridge may be said to be at “50%”.

DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a computing system;

FIG. 2 is a high-level block diagram of a printer;

FIG. 3 illustrates, schematically, a replaceable print cartridge;

FIG. 4A is a flow diagram illustrating, by way of example, certainaspects of the printer operation;

FIG. 4B illustrates how the printer may operate to periodically estimatethe remaining life of the cartridge; and

FIG. 5 is a graph for illustrating further, by way of example, theoperation of the printer to periodically estimate the remaining life ofthe cartridge.

FIG. 6 is a flow chart illustrating an aspect of the printer operation.

DESCRIPTION

Referring to FIG. 1, a computing system 102 is shown. The computingsystem 102 includes a computer 104 and a printer 106. The computer 104is connected to the printer 106 by a communication link 108.

The computer 104 may represent any type of computer that is capable oftransmitting a print job to the printer 106 over the communication link108. Thus, for example, the computer 104 may represent a personalcomputer, a laptop computer, a personal digital assistant (PDA), and thelike.

The printer 106 may represent any type of printing device. For example,the printer 106 may represent an ink printer or an electrophotographic(EP) printer. It is further noted that the printer 106 may represent amultifunctional device. For example, the printer 106 may permit awalk-up user to print copies of a hardcopy document and/or transmit afax.

The communication link 108 may represent any type of communicationsystem that enables the computer 104 to transmit electronic informationto the printer 106. Thus, for example, the communication link 108 mayrepresent a wired and/or a wireless type communication system. In someimplementations, for example, the communication link 108 may representan intranet and/or the Public Internet. In other implementations, forexample, the communication link 108 may represent a cable that directlyconnects the two devices.

FIG. 2 is a high-level block diagram of the printer 106. The printer106, in this example, includes the following: a controller 202, anInput-Output (I/O) port 210, a print engine 212, a replaceable cartridge214, a display panel 25 218 and a set of level sensors 220. The printer106 may include other components that are not shown. For example, theprinter 106 may include additional replaceable cartridges, a localcontrol panel, a hard drive, a scanning device, and the like.

The controller 202 orchestrates the operation of the printer 106. Asshown, the controller 202 includes, in this example, a processor 203 anda firmware module 205. Aspects of the controller 202 operation aretypically performed by the processor 203 while executing the firmwaremodule 205. The firmware module 203 is stored in a local memory 207.

The I/O port 210 enables the printer 106 to both receive data (e.g.,print job data) and to transmit data over the communication link 108.

The print engine 212 includes the appropriate hardware to enable theprinter 106 to print images on media. As indicated above, in someimplementations, the print engine 212 may represent an EP print engine.In other implementations, for example, the print engine 212 mayrepresent an ink print engine. It is noted that the print engine 212 maybe capable of printing on any number of media types. Including, forexample, opaque and/or transparent media. Also, in some implementations,the media may be in the form of paper sheets, paper rolls, plasticsheets (such as overhead transparencies), vellum sheets, envelopes,cardstock or the like. It is further noted that the print engine 212 mayenable the printer 106 to print images in color and/or in monochrome.

The replaceable cartridge 214 contains a print material that is utilizedby the print engine 212 to print. The print material may be, forexample, toner or ink. In this example, the cartridge 214 includes anintegrated memory component 215 that is used to store certain electronicdata. The memory component 215, in this example, is both readable andwriteable by the printer 106.

The level sensors 220 may include any type of sensor that can sense whenthe print material of the cartridge 214 is at a particular level. Thus,for example, the level sensors 220 may represent optic sensors and/orcapacitance sensors. The level sensors 220 may also be an integratedpart of the cartridge 214.

FIG. 3 illustrates, schematically, each one of the level sensors 220 andthe replaceable cartridge 214. The print material 301 contained by thecartridge 214 is also represented.

It is noted that FIG. 3 illustrates five pre-determined print materiallevels: Level “A”,“B”,“C”, “D” and “E”. Level “A” represents the levelof the print material 301 when the cartridge 214 is considered to be at100% capacity. It noted that Level “A” may be the expected printmaterial level prior to the cartridge 214 being used.

In this example, the level sensors 220 include four discrete sensors: afirst level sensor 302, a second level sensor 304, a third level sensor306 and a fourth level sensor 308. Each of these four sensors areconfigured and adapted to generate a signal when the level of the printmaterial 303 moves to one of the pre-determined levels. The controller202 is configured to monitor the level sensors for these signals.

The first level sensor 302, for example, generates a signal when theprint material level is at level “B”. It has been determined that whenthe print material 301 is at level B, approximately 25% of the printmaterial 301 has been 5 consumed. Thus, when the first level sensor 302generates a signal, the remaining life of the cartridge 214 is atapproximately “75%”. That is to say, 75% of the print material 301originally contained by the cartridge 214 remains.

The second level sensor 304 generates a signal when the print materiallevel is at level “C”. It has been determined that when the printmaterial 301 is at level C, approximately 50% of the print material 301has been consumed. Thus, when the second level sensor 304 generates asignal this indicates that the remaining life of the cartridge 214 is atapproximately “50%”.

The third level sensor 306 generates a signal when the print materiallevel is at level “D”. It has been determined that when the printmaterial 301 is at level “D”, approximately 75% of the print material301 has been consumed. Thus, when the third level sensor 306 generates asignal this indicates that the remaining life of the cartridge 214 is atapproximately “25%”.

The fourth level sensor 308 generates a signal when the print materiallevel is at level “E”. It has been determined that when the printmaterial 301 is at level E, approximately 95% of the print material 301has been consumed. Thus, when the fourth level sensor 308 generates asignal this indicates that the remaining life of the cartridge 214 is atapproximately “5%”.

Also shown in FIG. 3 is the cartridge memory component 215. As indicatedabove, in this implementation, the memory component 215 is an integratedcomponent of the replaceable cartridge 214. Stored in the memorycomponent 215 is data 310. In some implementations, the data 310 mayindicate an estimate of the remaining life of the cartridge 214. How theprinter 106 may calculate this estimate is discussed below.

As previously noted, the printer 106 is able to receive and processprint jobs. During the processing of these jobs, the print material 301contained by the cartridge 214 is typically consumed.

FIG. 4A is a flow diagram illustrating, by way of example, certainaspects of the printer operation. Referring to FIG. 4A, the cartridge214 is first installed into the printer 106. The printer 106 detects thepresence of the 35 cartridge 214 (step 402). In response, the printer106 operates to initialize a pixel count for the cartridge 214 (step406).

Thereafter, until the cartridge 214 is removed, the printer 106 operatesto count pixels (as jobs are processed) that are generated which utilizeprint material 301 from the cartridge 214 (step 408).

Additionally, the printer 106 operates to monitor the level sensors 220in order to detect an actual print material level (step 410). That is tosay, the printer 106 monitors the level sensors 220 to detect when theprint material 301 is at level “B”, “C”, “D” and “E”.

It is also noted that once the cartridge 214 is installed, the printer106 periodically estimates the remaining life of the cartridge 214. Inthis example, the printer 106 calculates these estimates using apre-determined function that relates the present remaining life of thecartridge 214 to the following values:

a) a reference print material level; and

b) the change in the pixel count since the print material 301 was at thereference level.

It is noted the reference print material level may be any past printmaterial level. It is further noted that the reference level may be anassumed level or a detected level.

As is discussed in greater detail below, the printer 106 may usedifferent reference levels during the life span of the cartridge 214 toestimate the remaining life of the cartridge 214. For ease of thefollowing discussion, the reference level presently being used, at anypoint in time, to estimate the remaining life of the cartridge 214 maybe referred to as the “current reference level”.

FIG. 4B illustrates how the printer 106 may operate to estimate theremaining life of the cartridge 214. Referring to FIG. 4B, after thecartridge 214 is installed in the printer 106, the printer 106 begins toperiodically estimate the remaining life of the cartridge 214 (step420).

In this example, an assumption is made that when the cartridge 214 isfirst installed, level “A” is the present print material level. Thus,prior to a signal being generated, the printer 106 calculates eachremaining life estimate using the following values:(a) level “A” as thecurrent reference level; and (b) the change in the pixel count since thecartridge 214 was first installed.

When the printer 106 detects an actual print material level (i.e., whenone of the four level sensors 220 generates a signal) (step 422), theprinter 106 then proceeds to calculate each remaining life estimateusing: (a) the last detected level as the current reference level; and(b) the number of pixels counted since the last detected level wasdetected (step 424).

FIG. 5 is a graph 502 for illustrating further, by way of example, theoperation of the printer 106 to periodically estimate the remaining lifeof the cartidge 214. The “X” axis of the paragraph 502 represents thepixels counted at step 408 during the life of the cartridge 214. Thefirst “Y” axis represents the remaining life estimates. The secondY-axis represents the corresponding print material level.

In this example, the following scenario is assumed:

a) The print material 301 is at level “A” when the cartridge 214 isfirst installed into the printer 106;

b) The first level sensor 302 generates a signal when the cartridgepixel count value reaches a value of “XI”;

c) The second level sensor 304 generates a signal when the 20 cartridgepixel count value reaches a pixel count value of “X2”;

d) The third level sensor 306 generates a signal when the cartridgepixel count reaches a pixel count value of “X3”; and

e) The fourth level sensor 308 generates a signal when the cartridgepixel count reaches a pixel count value of “X4”.

Referring now to FIG. 5, after the cartridge 214 is installed and untilan actual level is detected, the printer 106 operates to periodicallyestimate the remaining life of the cartridge 214 using level “A” as thecurrent reference level. The first curve 504 illustrates therelationship between the pixel count and the remaining life estimatesuntil the first actual level is detected.

At pixel count “X1”, the printer 106 detects that the actual printmaterial level is presently at “level B”. Thereafter, until the nextactual print material level is detected, the printer 106 periodicallyestimates the remaining life using level “B” as the current referencelevel. The second curve 506 illustrates the relationship between thepixel count and the remaining life estimates until the next actual levelis detected.

At pixel count “X2”, the printer 106 detects that the actual printmaterial level is presently at “level “C”. Thereafter, until the nextactual print material level is detected, the printer 106 periodicallyestimates the remaining life using level “C” as the current referencelevel. The third curve 508 illustrates the relationship between thepixel count and the remaining life estimates until the next actual levelis detected.

At pixel count “X3”, the printer 106 detects that the actual printmaterial level is presently at “level “D”. Thereafter, until the nextactual print material level is detected, the printer 106 periodicallyestimates the remaining life using level “D” as the current referencelevel. The fourth curve 510 illustrates the relationship between thepixel count and the remaining life estimates until the next actual level(level E) is detected.

It is noted that in some implementations, the cartridge memory component215 may include data (e.g., data 310) that indicates the presentremaining life of the cartridge 214. When the cartridge 214 is firstinstalled, the printer 106 may read this information and initially usethis information to determine the initial current reference level. Thiscurrent reference level may then be used to estimate the remaining lifeof the cartridge 214 until an actual level is detected. Also, inoperation, the printer 106 may periodically update the data in thecartridge memory component 215 to indicate the present remaining life ofthe cartridge 214. If the cartridge 214 is removed and then placed intoanother printer (printer “B”), printer “B” may then read and use thisinformation to determine the present remaining life of the cartridge214. Printer “B” may also use this information in a similar manner asprinter 106. That is to say, printer “B” may use this information to setan initial current reference level and then proceed to periodicallyestimate the remaining life of the cartridge 214.

FIG. 6 is a flow chart illustrating an additional aspect of the printer106 operation. Referring to FIG. 6, the printer 106 operates to detectwhen the estimated remaining cartridge life is below a “reorder”threshold (step 602). It has been determined that when the cartridgelife moves below this threshold, a new cartridge should be ordered. Inresponse to this condition, the printer 106 operates to transmit amessage that indicates the present remaining life estimate of thecartridge 214 (step 604).

The message may, for example, be transmitted to the computer 104 (seeFIG. 1) or sent to a particular e-mail account. The message may includeinformation to facilitate the re-order of the cartridge 214. Forexample, the message may indicate a part number of the cartridge 214.The message may also include a hyperlink to a WEB based server systemthat enables online ordering of the cartridge 214.

It is noted that the reorder threshold may be based in part upon therate at which the cartridge 214 is being depleted. In someimplementations, for example, the controller 202 operates to track thelife estimates over time in order to determine the depletion rate of theprint material 301. If the depletion rate is above a first threshold,the controller 202 sets the “reorder threshold” to a relatively highvalue. If, however, the depletion rate is below a second threshold, the“reorder threshold” is set to a relatively low value.

At step 606, the printer 106 operates to detect that the remaining lifeof the cartridge 214 is below 5%. In response, a message may bedisplayed on the display panel 218 indicating this condition (step 608).

It is further noted that the present invention may be embodied in theform of a “computer-readable medium”. As used herein, the phrase“computer-readable medium” can refer to any medium that can contain,store or propagate computer executable instructions. Thus, in thisdocument, the phrase “computer-readable medium” may refer to a mediumsuch as an optical storage device (e.g., a CD ROM) or a magnetic storagedevice (e.g., a magnetic tape). The phrase “computer-readable medium”may also refer to signals that are used to propagate the computerexecutable instructions over a network or a network system, such as thePublic Internet.

Thus, a memory component (e.g., memory 207) that stores computerexecutable instructions (e.g., firmware 205) may represent an embodimentof the invention. Furthermore, signals used to propagate the firmware205 over a communication link 108 (e.g. an intranet, Public Internet,etc) may also represent an embodiment of the invention.

Although several specific embodiments of the invention have beendescribed and illustrated, the invention is not to be limited tospecific forms or arrangements of parts so described and illustrated.The invention is limited only by the claims and the equivalents thereof.

What is claimed is:
 1. In a printer, a method of estimating theremaining life of a print cartridge containing a print material,comprising: (a) determining an actual level of print material in thecartridge each time a signal is generated by one of a plurality of printmaterial level sensors, where each sensor is configured to generate asignal when the print material is at a different one of a plurality ofpre-determined levels; (b) counting pixels that are printed utilizingprint material from the cartridge; and (c) periodically estimating theremaining life of the cartridge based upon the actual level determinedthe last time step (a) was performed and the number of pixels countedsince the last time step (a) was performed.
 2. The method of claim 1,wherein the print material is toner or ink.
 3. The method of claim 1,further comprising: (d) periodically storing the present estimate of theremaining life of the cartridge in a memory located on the cartridge. 4.The method of claim 1, further comprising: (d) determining that thepresent estimate of the remaining life of the cartridge is below a firstthreshold; (e) in response to step (d), transmitting a message; andwherein the message indicates that a replacement cartridge should beordered.
 5. A printer capable of utilizing a print material contained bya print cartridge to print, the printer comprising: (a) means fordetecting when the level of print material is at each of a plurality ofdifferent predetermined levels; (b) means for counting pixels; and (c)means for periodically estimating the remaining life of the cartridgeusing the last pre-determined level detected and by using the number ofpixels counted since the last pre-determined level was detected; andwherein the estimating means operates to periodically estimate theremaining life of the cartridge throughout the life of the cartridge. 6.The printer of claim 5, further comprising: (d) means for printing printjobs; and (e) wherein the pixel counting means operates to count thosepixels that are printed utilizing print material from the cartridge. 7.The printer of claim 5, wherein the cartridge includes an integratedmemory and the printer further comprises: (d) means for periodicallywriting data to the memory; and (e) wherein the data describes thepresent estimate of the remaining life of the cartridge.
 8. The printerof claim 5, further comprising: (d) means for transmitting a message toa pre-determined destination when the present estimate moves below athreshold; and (e) wherein the message indicates that a replacement forthe cartridge should be ordered.
 9. The printer of claim 5, furthercomprising: (d) means for transmitting an e-mail message to apre-determined destination; (e) wherein the message includes a hyperlinkto a particular WEB site; and (f) wherein the WEB site enables a user toplace a new order for the cartridge.
 10. A computer implemented controlsystem for a printer, the printer capable of utilizing print materialcontained by a cartridge, the system comprising: circuitry to receivesignals generated by a plurality of level sensors each for detectingwhen the level of the print material is at a different one of aplurality of pre-determined levels; processing circuitry, coupled to thesystem, configured to: (a) count pixels as print jobs are processed; (b)monitor the sensors over the life of the cartridge in order to detectwhen the print material is at each one of the pre-determined levels; and(c) periodically estimate the remaining life of the cartridge based uponthe last detected print material level and the number of pixels countedsince the last print material level was detected.
 11. The system ofclaim 10, wherein the processing circuitry is further configured to: (d)transmit a first warning when the estimated remaining life moves below afirst threshold; and (e) transmit a second warning if the estimatedremaining life moves below a second threshold.
 12. The system of claim10, wherein the processing circuitry is further configured to: (d) causean e-mail to be transmitted when the estimated remaining life movesbelow a first threshold; and (e) cause a message to be displayed if theestimated remaining life moves below a second threshold; wherein thefirst e-mail indicates that the cartridge will soon need to be replaced;wherein the message indicates that the cartridge should now be replaced.13. The system of claim 10, wherein the cartridge includes an integratedmemory component and the processing circuitry is further configured toperiodically write the present estimate of the remaining life of thecartridge to the memory.
 14. A printer, comprising: a print engine forprinting print jobs; and processing circuitry, coupled to the printengine; wherein the print engine utilizes print material contained by areplaceable print cartridge to print; wherein the cartridge includes aplurality of level sensors each configured to generate a signal when thelevel of print material moves to a unique one of a plurality ofpre-determined levels; and wherein the processing circuitry isconfigured to: (a) count pixels; (b) monitor the sensors over the lifeof the cartridge in order to detect when the print material is at eachone of the pre-determined levels; and (c) repeatedly estimate theremaining life of the cartridge using the last detected print materiallevel and the number of pixels counted since the last print materiallevel was detected.
 15. The printer of claim 14, wherein the cartridgeis a toner cartridge.
 16. The printer of claim 14, wherein the cartridgeis an ink cartridge.
 17. The printer of claim 14, wherein the printer iscapable of printing in color.
 18. The printer of claim 14, wherein theprocessing circuitry counts those pixels that are generated from thecartridge.
 19. The printer of claim 14, wherein the cartridge includesan integrated memory and the processing circuitry is configured toperiodically write data to the memory; wherein the data describes thepresent estimate of the remaining life.
 20. In a printer, a method ofperiodically estimating the present capacity of a print cartridge toprint additional pages, comprising: (a) detecting a plurality of actualprint material levels; (b) counting pixels; (c) estimating the presentcapacity of the cartridge to print additional pages; wherein step (c) isperformed based upon the last actual level detected and the number ofpixels counted since the last actual level was detected.
 21. The methodof claim 20, wherein step (c) is performed multiple times after step (a)is first performed.
 22. The method of claim 20, wherein the cartridgeincludes a memory component and the method further includes periodicallystoring the present estimate in the memory.
 23. In a printer, a methodcomprising: detecting the presence of a new print cartridge, where thecartridge includes a memory that stores an initial level value of printmaterial contained by the cartridge; in response to detecting thepresence of the cartridge, reading the initial level value from thememory; counting pixels as pages are printed by the printer;periodically estimating, until an actual print material level isdetected, the remaining life of the cartridge using the initial levelvalue and the number of pixels counted since the presence of thecartridge was detected; detecting a plurality of actual print materiallevels; and periodically estimating the remaining life of the cartridgebased upon the last actual level detected and the number of pixelscounted since the last actual level was detected.
 24. The method ofclaim 23, further comprising: periodically storing the present estimateof the remaining life of the cartridge in the memory.
 25. The method ofclaim 23, further comprising: transmitting a message when the estimatedremaining life falls below a first threshold; wherein the messageindicates that a replacement cartridge should be ordered.